500hp Ford Power Stroke Part 3

Turbo and Intercooler Upgrades

In the aftermarket, Turbonetics’ aluminum Spearco intercoolers are popular for almost every engine and are known for their ability to vastly cool exhaust gas temperature. We scored this unit off an ’00 7.3L Super Duty for next to nothing, as its original owner was actually going to scrap it. Other popular intercoolers for ’94½ to ’97 Power Strokes (which do a great job of cooling off EGT) include stock 7.3L units from ’99 to ’03 models, and even factory units off of 6.0L applications. Used 7.3L and 6.0L intercoolers can be found at your local junkyard, and they usually go for $150 to $200.

In the aftermarket, Turbonetics’ aluminum Spearco intercoolers are popular for almost ever

Installing a larger turbocharger and intercooler system is one of the best upgrades you can perform on a ’94½ to ’97 7.3L Power Stroke. And (as promised) that’s the direction we’re taking this month in our pursuit of 500 rwhp. We’re adding a new T4 turbo mounting system, an S300-based turbo, and a Spearco intercooler.

As a former ’97 Ford owner who’d installed his own intercooler, part owner of Randall’s Performance Corey Finch took on the job of fitting the Spearco behind our F-350’s grille. With essentially everything pulled off the front of the truck (grille, bumper, stone deflector, headlights), Finch located the areas of the radiator core support that had to be hacked to make everything work. He used a 5-inch hole saw blade to outline where the intercooler flanges would pass by the radiator.

As a former ’97 Ford owner who’d installed his own intercooler, part owner of Randall’s Pe

Groundbreaking Turbo Mount System
Even though the early 7.3L Power Stroke used the common T4 turbine inlet flange, the factory exhaust collector and short-length up-pipes mounted the Garrett TP38 turbocharger (which came with no map width enhancement groove) virtually on top of the driver-side valve cover. This tight packaging made it virtually impossible to mount a larger turbo using the stock pedestal, up-pipes, and collector. The 7.3L gurus at Irate Diesel Performance, who were already building complete T4 turbo mounting kits for ’99½ to ’03 Super Dutys, designed the breakthrough turbo mounting system we’re installing this month. Essentially, Irate’s T4 mount allows you to run any standard T4-equipped turbocharger on your ’94½ to ’03 7.3L (be it a BorgWarner, Garrett, or even Holset).

Using the hole saw blade as a template, Finch took a plasma cutter to the core support. Once the initial holes were made, the excess metal was removed with a Sawzall. Then he took a grinder to the rough-cut edges and hit the bare metal with a coat of white paint.

Using the hole saw blade as a template, Finch took a plasma cutter to the core support. On

In order to shoehorn the massive Spearco intercooler into place and install the new turbo system, we took our ’97 F-350 to Randall’s Performance in Gladstone, Illinois. Thanks to its expertise, our fabrication needs were a non-issue, and very few headaches surfaced when bolting on all the following upgrades. Make sure and tune in next month to see if we hit the 500hp mark on the dyno.

Our Goals
Make 500 hp at the rear wheels
Reduce EGT across the board (from cruising to wide-open throttle)
Increase turbo response with a higher-flowing charger
Installing a larger turbocharger and intercooler system is one of the best upgrades you can perform on a ’94½ to ’97 7.3L Power Stroke.

Because the original V-band flanges on our Spearco intercooler didn’t provide enough clearance around the radiator, we had to cut them off. Finch replaced them with smaller flanges off a 6.0L unit and had a local shop (which specializes in welding aluminum) weld them up for $65.

Because the original V-band flanges on our Spearco intercooler didn’t provide enough clear

Two stainless steel brackets, fabbed up by Finch, support the bottom of the intercooler (which rides on a 1/4-inch-thick piece of rubber). The top brackets were made from 2-inch x 1/4-inch pieces of flat steel. To both simplify and clean up the install, Finch installed nutserts for all bracket-mounting bolts.

Two stainless steel brackets, fabbed up by Finch, support the bottom of the intercooler (w

As the intercooler required the factory transmission cooler to mount closer to the grille, longer lines were needed. And although we considered upgrading to a larger aftermarket cooler at this point, the amount of additional cutting needed to make it work convinced us to tackle it later on.

As the intercooler required the factory transmission cooler to mount closer to the grille,

With the turbo, factory pedestal, and intercooler plumbing (from “ATS Diesel Intercooler System,” Jan. ’10) removed, Finch pulled the intake plenums. On ’94 1/2 to early ’99 7.3L engines, the formed steel intake plenums feeding each cylinder head have 2-inch inside diameter (id) inlets, whereas ’99 1/2-and-later engines were equipped with 3-inch inlet plenums. For us, removing the stock up-pipes and exhaust collector was easy since we replaced them last year (June ’11). Pulling the passenger-side plenum called for removing the glow plug relay, disconnecting the fuel supply line at the front of the head, and moving the high-pressure oil supply line out of the way.

Due to Irate’s turbo system utilizing 3-inch (id) piping, upgrading to a set of 3-inch inlet plenums (shown) from the ’99 1/2 to ’03 model year engine was a necessity—and a good thing. Thanks to Randy’s Engine and Machine, we found out just how restrictive our factory plenums were. We had a 2-inch inlet (’94 1/2 to ’99) plenum flow-tested, as well as these 3-inch inlet (’99 1/2 to ’03) units. The smaller plenum flowed just 241 cfm, while the larger plenum flowed 538 cfm.

Due to Irate’s turbo system utilizing 3-inch (id) piping, upgrading to a set of 3-inch inl

To keep our intercooler boots from blowing off, Finch rolled a bead around the Super Duty intake plenum inlets using Bead Form. Pushing the intake Y off the plenums is a common problem in high-boost applications, so giving the intercooler boots something extra to grab hold of is key.

To keep our intercooler boots from blowing off, Finch rolled a bead around the Super Duty

Because the intake plenums see a lot of boost, it’s not worth compromising on which material seals them to the cylinder heads. We used the same gasket maker that kept the stock plenums glued to the heads the past 16 years: Motorcraft TA-31 silicone sealant. Before installing the Super Duty plenums, Finch put rags in the heads and used a grinder with a Scotch-Brite pad to clean up the mating surfaces.

Because the intake plenums see a lot of boost, it’s not worth compromising on which materi

Moving on to the turbo system, Finch installed the new pedestal base, which mounts using the factory mounting pads on the block (for the factory pedestal). Finagling the up-pipe and collector assembly into place called for someone beneath the truck guiding the up-pipes onto the exhaust manifolds and someone pushing them down from up top. It was a tight fit, but thanks to the flexibility the bellowed up-pipes provide, it was a hassle-free process.

Moving on to the turbo system, Finch installed the new pedestal base, which mounts using t

Next came the turbo install, which calls for external oil supply and return lines. The new pedestal base from Irate effectively plugs off the factory oil drain location. In conjunction with the supplied oil line, 45-degree fittings, and new oil drain assembly, the factory bore in the block (originally used to mount the mechanical lift pump on ’94 1/2 to ’97 engines) becomes the new oil return (arrow). A threaded hole in the pedestal base allows the original oil supply location to be reused, and the supplied oil feed line that attaches to it can be seen here, loose behind the turbine housing. For good measure, Finch added some oil to the supply fitting on top of the center cartridge so the charger’s bearings wouldn’t be dry when initially starting the truck (we’ll go into detail on this turbo’s specs next month.)

Next came the turbo install, which calls for external oil supply and return lines. The new

The most time-consuming part of installing Irate’s turbo system was fitting the 3-inch downpipe between the engine and firewall, which is where a 10-ton Porta Power came in handy. And because we received one of its first kits for the ’94 1/2 to ’97 trucks, the downpipe was roughly 1 foot short of reaching our existing 4-inch MBRP exhaust system. To fill the gap, Finch welded a short piece of 3-inch flex pipe to it. We then wrapped the new assembly with Design Engineering exhaust wrap from Summit Racing, which is rated up to 2,000 degrees. As we went to press, Irate had since come up with a longer, direct-fit downpipe.

The most time-consuming part of installing Irate’s turbo system was fitting the 3-inch dow

Since the MAP sensor originally sat in the factory, 2-inch intake plenum on the passenger side of the engine, we had to relocate it to the intake Y (similar to the way it is on a Super Duty 7.3L). Luckily for us, Irate conveniently welds a threaded port into its aluminum intake Y. All it took was some extra hose and a 90 degree fitting with a 1/4-inch nipple and 1⁄8-inch NPT.

Since the MAP sensor originally sat in the factory, 2-inch intake plenum on the passenger

The last order of business entailed modifying the air intake. After installing Irate’s 45 degree rubber hose adapter to the turbo, Finch used a 5-inch-long (4-inch-diameter) section of stainless steel pipe to link the existing K&N system to the turbo (we also decided to retain the factory closed crankcase ventilation system rather than reroute it). After that, all supplied intercooler pipes were installed and secured via DieselSite silicone boots and spring-loaded, T-bolt clamps (chosen for their ability to hold as much as 100 psi of boost).

The last order of business entailed modifying the air intake. After installing Irate’s 45